The contract will support the Data Coordinating Centre of the World Health Organization Multi-National Study of Steroid Hormones and Cardiovascular Disease. This 14 nation study has been an ongoing case-control study of the risk of myocardial infarction and stroke in current and past oral contraceptive users. The NIH contract primarily provides for staff time at the central data processing and analysis centre of the WHO Study such that a series of primary, secondary, and tertiary analyses will be provided to the NIH. The University of London, accordingly, will deliver primary analytic results concerning the relative risks of stroke and myocardial infarction in Pill users compared to non-users. The secondary analytic runs will be delivered regarding the level of risk in women with one or more established cardiovascular risk factors. Finally, tertiary analyses will be delivered to the NIH concerning specific effects of particular oral contraceptive "Pill" effects, such as those attributable to estrogens or progestins. In addition to the analysis, the University of London, through a subcontract with Oxford University, will augment the data collection effort and increase the number of cases into the case-control study through the inclusion of English women living in the Oxford Health Authority region. A separate analysis of stroke from this centre will be a specific deliverable of Oxford University.